System and method for measuring sun-induced chlorophyll fluorescence

Abstract

A chlorophyll fluorescence measuring system having at least one spectrometer coupled to a data logger. The data logger provides direct control of the spectrometer and includes on-board memory for storage of target and reference spectrum data obtained by the spectrometer. The data logger may be coupled to an external computer that receives and analyzes target and reference spectrum data to determine SIF using a spectral fitting algorithm. The system may include a spectrometer aiming system coupled to and controlled by the data logger. The system may also include one or more environmental sensors configured to measure environment variables. The environmental sensors may be coupled to the data logger for control and data storage. The environmental data may be communicated to the external computer for use in the spectral fitting algorithm. The data logger may be connected to a network for remote monitoring and control.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0001]This invention was made with government support under Contract No. DE-AC05-00OR22725 awarded by the U.S. Department of Energy. The government has certain rights in the invention.FIELD OF THE INVENTION[0002]The present invention relates to systems and methods for measuring sun-induced chlorophyll fluorescence, and more particularly to systems and methods to provide automated measurement of sun-induced chlorophyll fluorescence.BACKGROUND OF THE INVENTION[0003]The foundation of our biosphere and civilization rests on the food and energy produced by plants using sunlight. Yet currently there is no commercially available technology that can measure, continuously and unattended, plant photosynthesis and physiological stresses in natural environments.[0004]Except for a few organisms that live off the heat and methane from hydrothermal vents at ocean bottoms, all life on Earth depends on photosynthesis by plants under sun...

AI Technical Summary

Benefits of technology

[0018]The present invention provides a simple and effective sun-induced chlorophyll Fluorescence Auto-Measurement Equipment (FAME) system that is capable of automatically and continuously measuring sun-induced chlorophyll fluorescence of plants growing in sunlight. The FAME system can be applied at scales of leaf, individual plant, or canopy in the field. Sun-Induced chlorophyll Fluorescence (SIF) is emitted from the core of the photosynthetic machinery of plant and is a vital signal of photosynthesis and physiological stresses. The FAME system allows for unattended, continuous operation and data capture of spectrum data and environmental data relevant to SIF. The FAME system is empowered by a number of hardware and software innovations that make it unprecedented in data quality, acquisition rate, versatility, extensibility, and easiness to operate. It is a high-performance integration of software and hardware technologies. The present invention allows for the production of a truly portable, rugged, and commercially viable instrument for continuous and unattended plant photosynthesis and stress monitoring in the field for scientist and agricultural practitioners. Through hardware and software innovations and system integration, the FAME system removes the constraints of conventional systems so that routine high-quality SIF monitoring is possible for ecological research and agricultural practices.

Problems solved by technology

Yet currently there is no commercially available technology that can measure, continuously and unattended, plant photosynthesis and physiological stresses in natural environments.

Despite of this importance, our present understanding remains poor with respect to plant photosynthesis and its relationship to growth conditions in natural environments.

This poor understanding has direct consequences for a variety of areas ranging from crop management to global carbon cycle modeling.

Part of the problem is caused by the lack of appropriate technologies that can conduct continuous and unattended monitoring of plant photosynthesis and physiological stresses in volatile and unpredictable conditions at multiple spatial and temporal scales.

However, measuring sun-induced chlorophyll fluorescence (SIF) in natural environments is a considerably bigger challenge because the spectrum of SIF overlaps that of reflected solar irradiance which is overall a much stronger (˜100 times) signal and therefore it is difficult to disentangle SIF from background interference.

This challenge explains why so far there has been no commercially available technology that can conduct continuous and unattended measurements of SIF on plants growing in the field.

These homemade systems are laborious to use because they require continuous manual supervision via a laptop computer.

Also other independent measurement systems have to be deployed to measure any additional variables needed to interpret the SIF signal, increasing burdens in both time and cost to researchers.

These constraints have limited SIF measurements and applications to a fraction of researchers who are most electronically savvy.

Images